Gas-check pad.



No. 822,644. 7 PATENTBD JUNE 5, 1906. E. A. YARNBLL. GAS CHECK PAD.

APPLICATION FILED JUNE 21. 1905.

meaaea: 17606766071 UNTTED gTATES PATENT OFFICE.

GAS-CHECK PAD.

Specification of Letters Patent.

Patented June 5, 1906.

Application filed June 21, 1905. Serial No. 1

To all whom it may concern:

Be it known that I, EUGENE A. YARNELL, a citizen of the United States,and a resident of Washington, District of Columbia, have inventedcertain new and useful Improvements in Gas-Check Pads, of which thefollowing is a full, clear, and exact description.

My invention relates to gas-check pads for breech-loading ordnance; andthe objects of my improvements are, first, to provide a pad which willnot be injured by the hot powdergases; second, to provide one which willexpand sufficiently to prevent the escape of the powder gases, yet notsufficiently to cause it to stick in the bore of the gun, thuspreventing the removal of the breech-block, and, third, to so simplifythe structure as to render it easier and quicker to manufacture. Iattain these objects in the structure shown in the drawings, in whichFigure I is a crosssection on the line I I of Fig. 11. Fig. 11 is a planview of the pad.

The body or filling of my pad is composed of a plurality of disks A, ofasbestos millboard dipped in tallow or other suitable grease. The disksare cut from sheets of the millboard and of such sizes so that when theyare assembled and pressed together they form an annular body ofsubstantially the shape shown in the drawings. Pads so constructed oflayers are fairly rigid and not easily bent out of shape under pressure,yet they are sufficiently expansible to thoroughly and efficiently sealthe space between the breech-block and the bore of the gun at the timeof the explosion. The pads in use at present and of which the fillingmaterial is composed of a semiplastic mass of asbestos fiber and talloware often expanded to such a degree under the influence of heat and theenormous pressure exerted that they bind against the bore of the gun,and it is impossible to remove the breech-block until the gun has cooleddown. This practically puts the gun out of action and constitutes a veryserious handicap; but when the body is composed of layers of asbestosmillboard it is not plastic, but under pressure does expand enough toaccomplish the objects for which it is usednamely, to seal the breechagainst the escape of powder-gases.

The cover of my new and improved pad is composed of but two pieces, bothof which may be made of asbestos cloth, or only the outer one may be ofasbestos cloth and the inner one of canvas or any other suitablematerial. These two pieces C and D are made from strips sewed togetherat the ends to form annular pieces. The piece D is placed within thecentral opening of the pad and the edges carefully stretched and presseduntil they fit the surface. The larger piece 0 is stretched over the padand the edges fitted down to the surface, which can be easily done, dueto the flexibility of the asbestos cloth employed. The two pieces arethen sewed together along the lines 0 and d, the pad dipped in tallow,and, if desired or found necessary, it may be pressed to the desiredshape. The asbestos cloth which I employ is very closely woven, and thusthoroughly protects the body, so that none of the fibers of the body cancome out between the meshes and be worn off. The only part of the coverwhich comes in contact with the hot powdergases is a strip around thecircumference of thepiece C, and therefore the piece D need notnecessarily be made of asbestos.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. A gas-check pad comprising a suitable cover and a body formed of aplurality of layers of asbestos millboard.

2. A gas-check pad comprising a plurality of layers of asbestos, and acover composed of two pieces, one of which is asbestos.

3. A gas-check pad formed of a plurality of layers of fibrousnon-metallic material and an asbestos cover inclosing the same.

4. A gas-check pad having a suitable body portion made up from aplurality of layers and a cover concealing and protecting the bodyportion, the said cover being formed from two annular pieces ofasbestos.

5. A gas-check pad having a suitable body portion formed substantiallyfrom layers of non-metallic fibrous mineral material and having a coverprovided with an annular piece fitting the central aperture and a secondannular piece fitting the outer circumference.

6. A gas-cheek pad with a suitable body portion formed substantiallyfrom independent yet permanent layers and reinforced by a cover ofasbestos material.

7. A gas-cheek pad having a suitable cover Witnesses: and a body made upof a plurality of layers J NO. WILsoN, of non-metallic fibrous material.CARRIE YARNELL.

Signed at Washington, District of C0lu1nbia, this 20th day of June,1905.

EUGENE A. YARNELL

